Dam



Jan.v7, 1930. E. PRoBs-r Er AL 1,742,369

DAll

Filed Nov. 12, 1928 u df ZM/6427277; Mz QM Patented Jan. 7, Y1930 EMIL PROBST AND FRIEDRICH TLKE, OIE KARLSRUHE, GERMANY DAM Application led November 12V, 1928, Serial No. 318,691, and in Germany August 1, 1928.

Our invention relates to dams and has for its object the economical and statically safe lconstruct-ion of solid dams for small andV medium-sized openings.

ln the annexed drawing in which we have illustrated our invention, Fig. l is a top plan view of the dam, Fig. 2 a view from the tailwater side, Fig. 3 a transverse section along line Hllll in Fig. 2, and Fig. 4 a section along line IV-IV in Fig. 2. Fig. 5 shows on a larger scale the intermediate layer between the lower and upper portions of the dam, while Fig. 6 is asimilar view as Fig.

3 showing a modification.

The dam comprises a lower portion of the gravity type dam composed of a plurality of blocks a deeply built into the solid roclr and separated by joints f of a Width sufficiently great to present an arch effect in said lower dam portion, an upper portion l) of the arched dam type, and a highly plastic intermediate portion, or layer ci.

The lower portion composed of the blocks (t has a horizontal top surface, provided with a smooth cement dressing. surfaces on the air-side and on the water-side is determined by the static and structural requirements. Y

The joints f, which are perpendicular, are preferably offset as shown in Fig. 4, and for the purpose of preventing any water from seeping through, they are closed on the waterside, as for instance by a suitably shaped .sheet metal strip of copper.

The intermediate layer consists of a highly plastic material so as to enable a slight perpendicular and horizontal relative displacement to occur between the upper dam portion ZJ and the lower dam portion t without presenting any noticeable resistance. Y V The arrangement of the intermediate layer l is illustrated in Fig. 5. On the air-side it abuts against shoulders h and z' of the upper` dam portion b, and the lower dam portion a which are preferably armored againsty lateral thrust.. The gap separating the two shoulders is sc dimensioned that irrespective of any load there is no contact. On the water side, the intermediate layer rests against a shoulder la, likewise preferably armored, of

The shapeof the the lower dam portion a. And as to the size Y ofthe gap, the same applies as regards the gap on the air-side. For preventing any. water to leak through on the water-side, the gap is closed by aV yieldingly disposed sheetmetal strip a of copper, which, if desired can be covered. In the design of this construction, it was taken into consideration that a horizontal relative displacement can occur only in this way that the upper dam portion is displaced relative to the lower dam portion av on the air-side, as is usually the case. The upper dam portion ZJ consists. of a barrel vault of varying thickness and having enlargements on the imposts or piers 0. Preferably, the aXis of the barrel vault is perpendicular. The perpendicular radially extending joints g are serrated, as. shown in Fig. 4. For preventing any leakage, they are covered on the water side by a 'sealing means, e. g., sheet-metal ofcopper. Tomake thevault ventirely safe, the joints are Vcast after they have become hardened between the seal on the water-side and the outer edge on theV air-side. K

The width of the upper part of the upper darn portion b which part, as shown in Fig. t is of uniform thickness, is determined by vthe width of the top of the dam which usually also serves yet other purposes.

In order to prevent any undesirable static secondary effects, the modified construction shown in Fig. 6 is frequently preferred. The cross-section of the vault above the hydromechanical minimum strength is calculated according to purely staticA and structural view points. The solid or open structure top plate rests on the -water-side on the barrel vault, while on the air-side it is supported by thev dam by means of a plurality of urpights s. In order to avoid an undesired static strain of the top plate and the barrel vault, the plate p must loose-ly rest on the vault b.

For the dam as shown in the drawing, it is advisable to make the lower darn portion a about half the height of the upper dam portion b. Fordeep valleys of more V-shaped cross-sectiomthe two dam portions are more or less of the same height, and in especial cases, it may be even economical, to' make the 2 -f l l 1,742,369

lower dam portion a higher than the upper relative thereto, and a layer of plastic madam portion b. rlhe height of the upper darn terial between said dam portions.

portion Z) may be determined from the following point of view. For reasons of construction, the center angle ot the barrel vault for the upper dam portion b is made as large as the proile of the valley will permit; Now, the smallest center angle, directly above the intermediate layer (l, should not be siibstaiitially less thanlOO degrees. How much one may deviate from this minimum angle, is a pure question of the shape of the valley and of economy.

The invention comprises dams both of masonry and of concrete, armored or unarmored.

An armoui` will be advisable, where the static conditions involve higher tensional stresses than is permissible for concrete.

in order to aii'orda guide, one might say that the invention permits to' economically construct dams oi concrete only for a width of valley oi' about Ll-OO it. and a pressure head 0I" about 130 ft. Gnly in excess of these dimensions, an armour will have to be considered, but, of course, onlyV in the upper dani portion Z), and iron members are .required only near the piers or imposts on the waterside. They are preferably anchored inthe enlarged portions c.

The particular object of the invention is to produce a dam wall, in which the transmission of Jforces can be readily and quickly recognized, aside from the tact that the dam wall is extremely economical, as the arch eff feet is eliminated where the gravity eiect makes stability possible in the simplest manner. i Moreover, the invention, because of the enlargements at c, involves a considerable reduction in the pressure at the piers or imposts Teclaim p 1. A dam comprising a lowerportion of the gravity danitype, a top portion of the arched Vdam type, and means to prevent an arch effect in said lower dam portion, said top dam portion being mounted on said lower dam portion so as to be capable of displacement relative thereto.

2. A dam comprisincv a lower portion of the gravity dam type and a top portion of the arched dam type, said topdam portion being mounted on said lower dam portion so as to be capable of displacement relativev thereto', said lower gravity type damportion being composed of a plurality of separate blocks, and joints between said blocks of a width sufiiciently great to prevent an arch eect in said lower dam portion.

3. A damcomprising a'lower dam portion l' portion being mounted on said lower dani portion so as to be capable ot displacement ln testimony whereof we aiiiX our signatures. 

